Segments - Information regarding reportable segments (Details) - USD ($) $ in Thousands		3 Months Ended
		Apr. 30, 2017	Apr. 30, 2016
Segment Reporting Information [Line Items]
Net sales		$ 529,042	$ 457,403
Cost of goods sold		327,186	291,734
Gross profit		201,856	165,669
Selling, general and administrative		197,411	153,105
Depreciation and amortization		9,838	7,193
Operating profit (loss)		(5,393)	5,371
Operating Segments | Wholesale
Segment Reporting Information [Line Items]
Net sales		453,017	382,371
Cost of goods sold		298,373	257,995
Gross profit		154,644	124,376
Selling, general and administrative		130,160	96,938
Depreciation and amortization		6,385	5,000
Operating profit (loss)		18,099	22,438
Operating Segments | Retail
Segment Reporting Information [Line Items]
Net sales		99,185	94,992
Cost of goods sold		51,973	53,699
Gross profit		47,212	41,293
Selling, general and administrative		67,251	56,167
Depreciation and amortization		3,453	2,193
Operating profit (loss)		(23,492)	(17,067)
Elimination
Segment Reporting Information [Line Items]
Net sales	[1]	(23,160)	(19,960)
Cost of goods sold	[1]	(23,160)	(19,960)
Gross profit	[1]
Selling, general and administrative	[1]
Depreciation and amortization	[1]
Operating profit (loss)	[1]

[1] Represents intersegment sales to the Company's retail operations.